The present invention relates generally to agricultural implements and more particularly to seeding implements such as grain drills and the like.
Presently existing opener points or shovels utilized with implements such as grain drills generally are of the type that undermine the dirt and plow out a groove for seed. The undermined dirt flows up the shovel or point and has to be divided and thrown off to the side of the opener shank. The distance the dirt is thrown depends upon the amount of dirt picked up, the shank width and the forward speed. In sticky ground conditions, dirt buids up on the shank and causes more dirt throwing. If a runner type of opener is utilized, stalks and other type of trash can hairpin around the runner and render the opener ineffective.
Narrow row seeding can be a problem with presently existing opener points or shovels since it is common for one shovel to throw dirt over a furrow formed by adjacent shovels. The difference in dirt cover effects the growth of the plant, and it is not uncommon to see one row of plants emerge from the ground sooner than an adjacent row. This problem is wholly unacceptable to the farmer, and becomes more acute as he increases the forward speed of the seeding implement to increase productivity. Approaches to solving the dirt-throwing problem include staggering the furrow openers, adding dirt guards around the openers to reduce lateral throwing of the dirt, and adding press wheels which tend to push some of the excess dirt off of the opener rows. These approaches have not been entirely satisfactory in all respects. Staggering the openers does increase trash clearance, but more dirt is still thrown over the rows formed by the forward furrow openers. Shields and additional press wheels increase the expense and complexity of the implement.
Various runner or slicing type of attachments are available for planters, but these are generally utilized with cutting discs to form a slice below the edge of the discs. Many of the runner and slicing type of openers have a relatively large fore-and-aft dimension so that the forward end of the opener is offset a substantial distance ahead of the seed tube. Therefore, exact positioning of the opener on the standard and tight control of the angle of the standard with respect to the vertical is necessary to maintain the proper relationship between the opener and the seed tube. Since many opener assemblies are spring biased into contact with the ground, changes in attitude of the standard are common as the opener encounters various ground conditions. As a result, the relationship between the opener and the seed tube can vary enough to cause unacceptable irregularities in seed placement. In dry conditions, the seed must be deposited relatively deeply in moist soil for good germination, and any substantial change in the relationship between the opener and the seed tube can adversely effect the placement of the seed. Another disadvantage of the relatively long runner or slicing type opener is that side bend forces are increased in proportion to the length of the opener. Trash clearance is also reduced between the opener and the adjacent openers when a long runner or slicer is utilized. The greater the distance between the forward edge of the opener and the lower portion of the supporting standard, the greater the variation in the front edge location with respect to the ground surface as the standard trips in varying ground conditions. For example, in hard soils, the standard will tend to trip rearwardly and therefore cause the front of the runner to point downwardly. In soft ground, the opposite will happen and the point will lift upwardly as the standard rocks ahead. Most runner and slicer type of blades either have a forward nose that extends above the surface of the ground or are used in combination with disc openers, so that at in either situation hairpinning of trash is a common problem. Therefore, problems can easily occur in trashy conditions such as when the openers are utilized in minimum tillage situations. Stub runners have been available for planting corn or the like in rough, trashy conditions to eliminate some hairpinning problems, but these runners have a relatively long dimension in the fore-and-aft direction so that they too are subject to many of the disadvantages noted above.